Re: copy and paste error in rb tree code

[Philip Guenther]

On Mon, Oct 8, 2018 at 6:03 PM David Gwynne <da...@gwynne.id.au> wrote:

> According to https://github.com/FRRouting/frr/pull/3106, Coverity thinks
> I made a copy and paste error regarding one of the augment calls in
> RBT_REMOVE. I'm inclined to agree.
>
> The augment code is only used by uvm_map.c, and it seems to be fine with
> this change. I believe it coped because the augment handler it provides
> is very conservative and walks all parents on every augment call, so
> the code missing one wasn't a problem.
>
> ok?
>

Looking at the macro code this was based on in tree.h rev 1.14, I agree
it's wrong and the diff is correct:
...
                         if (RB_LEFT(RB_PARENT(old, field), field) == old)\
                                RB_LEFT(RB_PARENT(old, field), field) =
elm;\
                        else                                            \
                                RB_RIGHT(RB_PARENT(old, field), field) =
elm;\
                        RB_AUGMENT(RB_PARENT(old, field));              \
...

ok guenther@